Ludwig Wittgenstein

Best known as: The Austrian-English philosopher who wrote Tractatus and Investigations

Name at birth: Ludwig Josef Johann Wittgenstein

Ludwig Wittgenstein was an influential analytic philosopher of the 20th century. He is known mainly for his two works Tractatus Logico-Philosophicus (1921) and Philosophical Investigations (1953). One of eight children from a wealthy Austrian family, he studied mechanical engineering in Berlin (1906-08) and aeronautical engineering in England at Manchester U. (1908-11) before going to Cambridge, where he studied philosophy with mathematician Bertrand Russell ((1912-13). Wittgenstein served in the Austrian army during World War I, famously filling his rucksack full of notes that would later become Tractatus. He finished the work in a POW camp in Italy, and after its publication Wittgenstein gave up his share of the family fortune and worked as a teacher and monastery gardener. Meanwhile, awed Viennese philosophers were poring over his work on the nature and limits of language. In 1929 he returned to the world of academia at Cambridge, where he would spend the rest of his career. (He became a naturalized British citizen in 1938.) He was a renowned teacher and lecturer, but didn't publish again in his lifetime. Investigations was published after he died, and since then his work has been generally split into Early Wittgenstein (Tractatus) and Late Wittgenstein (Investigations), with much argument about whether the two works are diametrically opposed or part of an evolving philosophy. In his early work he argued there was a precise relationship between language and reality. In his later work Wittgenstein criticized that notion and said language was a tool for a shared context, not necessarily a formal link to reality. Since his death his notes, lectures and letters have been published and debated, and he's considered one of the greats in the western philosophical tradition.

Extra credit: Three of Wittgenstein's brothers committed suicide... His brother Paul was a concert pianist -- even after losing his right arm in World War I... One of his sisters, Margaret, corresponded with Sigmund Freud and was painted in 1905 by Gustav Klimt.